Camera module, imaging system, and mobile object

Abstract

Provided is a camera module in which fastening between housings by means of screws is allowed without impairing airtightness inside the housings, attained by using a seal member, while making it possible to realize a compact camera size. Also provided are an imaging system and a mobile object.　A camera module according to the present invention is configured such that screws 80 themselves, screwed into a first housing 23 from a second housing 24 side in order to fasten the first housing 23 and the second housing 24 together, fix a seal member 70 to the second housing 24 at positions not interfering with an imaging module 310, the seal member 70 being interposed between the second housing 24 and a third housing.

Description

Camera module, imaging system, and mobile object

[0001] The present invention relates to a camera module such as an in-vehicle camera mounted on a vehicle such as an automobile, an imaging system, and a mobile object equipped with an imaging system.

[0002] Conventionally, automobiles have been equipped with on-board cameras to assist with parking and prevent collisions through image recognition, and attempts have also been made to apply such cameras to autonomous driving. In addition, a camera module such as an on-board camera generally includes a lens unit having a lens group formed by a plurality of lenses arranged along an optical axis, a lens barrel that houses and holds the lens group, and an aperture member disposed between at least one of the lenses in the lens group (see, for example, Patent Document 1).

[0003] Furthermore, such lens units may be attached to a mounting portion such as the front grille of a vehicle (automobile), with the lens closest to the object exposed to the outside. In such cases, foreign matter such as water droplets, muddy water, ice, snow, and frost easily adheres to the surface of the lens. If this happens, it is necessary to remove the foreign matter to ensure a clear field of view for observation using the lens unit.

[0004] In recent years, foreign matter adhering to the surface of a lens (or lens cover) has been removed by vibrating the lens (or lens cover) with a vibrating body (ultrasonic vibration). For example, in Patent Document 2, a vibrating device for removing foreign matter such as water droplets and dust adhering to a dome-shaped cover (lens cover) is provided in a camera equipped with a lens unit.

[0005] Specifically, as shown in Figure 6, such a vibration device 102 is provided in a camera that has an imaging unit 105 with a lens 106 and a circuit including an imaging element built in at the top of the camera body 103, and is equipped with a dome-shaped transparent cover 111, a cylindrical vibrating body 112 to which the cover 111 is fixed, and a piezoelectric element 113 that is fixed to the vibrating body 112 and vibrates the cover 111 via the vibrating body 112. The vibrating body 112 has a cylindrical portion 114 having a first end 114a located on the cover 111 side and a second end 114b located on the opposite side from the cover 111, a cylindrical first connecting portion 115 connected to the first end 114a of the cylindrical portion 114 and consisting of a cylinder with an inner diameter larger than that of the cylindrical portion 114, a first ring-shaped portion 116 interposed between the first connecting portion 115 and the cover 111 and having an inner diameter smaller than that of the first connecting portion 115, a second connecting portion 117 connected to the second end 114b of the cylindrical portion 114 and consisting of a cylinder with an outer diameter smaller than that of the cylindrical portion 114, and a second ring-shaped portion 118 interposed between the second connecting portion 117 and the piezoelectric element 113 and having an outer diameter larger than that of the second connecting portion 117.

[0006] In such a vibration device 102, by driving the piezoelectric element 113 and ultrasonically vibrating the cover 111 via the vibrating body 112, the movement and atomization of droplets can be more effectively achieved, or foreign matter adhering to the surface of the cover 111 can be removed.

[0007] JP 2013-231993 A Japanese Patent No. 6977784 A

[0008] Incidentally, all of the components of such a compact camera module, including the camera body 103 and the vibration device 102, are housed within a housing 130. In this case, the housing 130 may be constructed by joining multiple housing parts together for reasons such as ease of assembly of the camera components. In particular, when, for reasons of ease of assembly or design, the housing 130 is constructed from a cylindrical first housing that forms an internal storage space for accommodating the vibration device 102 and the lens unit including the lens 106 and the lens barrel, a substantially thin-walled, dish-shaped second housing that forms a recess that primarily accommodates the board portion of the image sensor module (imaging module) that constitutes the imaging unit 105 on which the imaging element is mounted, and a cylindrical third housing that forms an internal storage space for accommodating most of the image sensor module and part of the extension from the image sensor module, a problem may arise. This will be described below.

[0009] In the split housing structure described above, the housings must be fastened together with screws, and a seal must be interposed between the joints of the housings to maintain airtightness within the housings. In this case, the image sensor module, which occupies most of the interior space of the second and third housings, is generally positioned at the center of the interior of the second and third housings, and the seal is disposed on the outer periphery of the housings to ensure sufficient airtightness. Therefore, the screws for fastening the housings together are disposed on the outer periphery of the housings, between the image sensor module and the seal, close to the seal. In particular, it is difficult to secure the installation position for the screws in the second housing, which is generally thin-walled and dish-shaped and has limited installation space.

[0010] That is, as an example, as shown in Figures 7 and 8, when the image sensor module 155 occupies most of the inner space of the second housing 130B and the sealing member 140 is arranged on the outer periphery of the second housing 130B, screws 142 for fastening the first housing 130A and the second housing 130B together are arranged at four locations (four corners in the figures) on the outer periphery of the second housing 130B, close to the sealing member 140, between the image sensor module 155 and the sealing member 140. In this case, as described above, the inside of first housing 130A is densely packed with components including camera body 103 and vibration device 102, and assembly is also performed in order from first housing 130A to second housing 130B and third housing (not shown), so generally, screw 142 is screwed into first housing 130A from the second housing 130B side, with the head of screw 142 positioned on the second housing 130B side. Note that a rubber washer 144 is interposed between the head of screw 142 and second housing 130B, and sealing member 140 has an annular shape disposed in groove 150 formed around the entire periphery of second housing 130B along the inner outer periphery, and is positioned by groove 150.

[0011] Therefore, in a situation where the installation space for camera components is limited, and with the recent increasing demand for smaller cameras, it becomes necessary to position the screw 142 further outward to avoid interference between the screw 142 and the image sensor module 155. As a result, there is a concern that the head of the screw 142 will interfere with the sealing member 140, adversely affecting the airtightness of the sealing member 140.

[0012] The present invention has been made in consideration of the above circumstances, and aims to provide a camera module, an imaging system, and a mobile body that enable the camera to be miniaturized while ensuring that housings are fastened together with screws without compromising the airtightness inside the housing provided by the sealing member.

[0013] In order to solve the above problem, the present invention provides a camera module comprising a lens group in which a plurality of lenses are arranged along the optical axes of the lenses, a lens barrel that houses and holds the lens group, and an image sensor that converts light collected through the lens group into an electrical signal, the camera module comprising: a cylindrical first housing that forms an accommodation space inside to receive the lens barrel that houses and holds the lens group; a second housing that is coupled to the image side of the first housing and forms a recess that receives a board on which the image sensor is mounted so that the image sensor faces the lens group; a cylindrical third housing that is coupled to the image side of the second housing and surrounds the image sensor module including the board from the outside; screws that are screwed into the first housing from the second housing side to fasten the first housing and the second housing together; and a seal member that is interposed between the second housing and the third housing, the seal member being arranged around the entire circumference so as to follow the inner outer periphery of the second housing, and being fixed to the second housing by the screws at a position where the image sensor and the screws do not interfere with each other.

[0014] According to the above-described configuration of the present invention, the screws that are screwed into the first housing from the second housing side to fasten the first and second housings secure the seal member to the second housing at a position that does not interfere with the imaging module. Therefore, even in situations where the installation space for the second housing is limited due to the miniaturization of cameras, the fastening of the housings by the screws can be ensured without compromising the airtightness of the interior of the housings provided by the seal member. In other words, because the screws for fastening the housings are integrated with the seal member and also serve as fixing screws for the seal member, the conventional problem of having to position the screws further outward to avoid interference between the screws and the imaging module, such that the screw heads adversely affect the sealing properties of the seal member, is avoided. Furthermore, because the seal member is fixed by screws, there is no need to form grooves in the second housing for accommodating and positioning the seal member, as in the conventional case.

[0015] In the above configuration of the present invention, the seal member preferably has a plurality of screw engagement portions into which screws can be engaged to secure the seal member and fasten the first and second housings together. In this case, the screw engagement portion preferably has an insertion hole for inserting the shank of a screw that penetrates the second housing and threads into the first housing, and a washer operating portion (a portion that acts as a washer) that is interposed between the head of the screw and the second housing. This allows the seal member and the washer to be formed integrally, eliminating the need to assemble a separate washer used in fastening the screws.

[0016] In the above-described configuration of the present invention, the screw engagement portion preferably forms a peripheral side wall that surrounds the entire periphery of the head of the screw. Alternatively, the screw engagement portion preferably forms a recess for embedding the head of the screw inside the sealing member. In this way, the head of the screw is covered by the sealing member, preventing the head of the screw from adversely affecting the sealing performance between the second housing and the third housing.

[0017] In the above-described configuration of the present invention, it is preferable that the first housing further includes a vibration mechanism having a vibrator for vibrating the first lens of the lens group that is positioned closest to the object. This makes it possible to remove foreign matter such as water droplets and dust adhering to the lens (or lens cover) by vibration, thereby ensuring a clear field of view at all times.

[0018] The present invention also provides an in-vehicle system having the above-mentioned camera module, and a mobile body equipped with the in-vehicle system. Such in-vehicle systems and mobile bodies can achieve the same effects as the above-mentioned camera module. Note that the term "mobile body" refers to any object that can move, such as a vehicle.

[0019] According to the camera module of the present invention, it is possible to reduce the size of the camera, while ensuring that the housings can be fastened together with screws without compromising the airtightness inside the housings provided by the sealing member.

[0020] 7 is a schematic cross-sectional view of a camera module according to an embodiment of the present invention. (a) is a plan view of the second housing of the camera module of FIG. 1 as seen from the side of the third housing, and (b) is a cross-sectional view taken along line A-A in (a). 7 is a schematic partial perspective view of a screw engagement portion in the second housing of FIG. 2. 7 is a schematic diagram of a vehicle as a moving body on which an imaging system (on-board system) including a camera module according to an embodiment of the present invention is mounted. 7 is a block diagram showing the configuration of an imaging device constituting the imaging system of FIG. 4. 7 is a schematic cross-sectional view of a conventional camera module. (a) is a plan view of the second housing of another conventional camera module as seen from the side of the third housing, and (b) is a cross-sectional view taken along line B-B in (a). 7 is a schematic partial perspective view of a screw fastening portion and a sealing member in the second housing of FIG.

[0021] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present embodiments contribute to the achievement of "9. Industry, innovation and infrastructure" of the Sustainable Development Goals (SDGs) advocated by the United Nations, which states, "9.1 Develop quality, reliable, sustainable and resilient infrastructure, including regional and transborder infrastructure, to support economic development and human well-being, with a focus on affordable and equitable access for all."

[0022] 1 is a schematic cross-sectional view of a camera module 300 according to an embodiment of the present invention. The camera module described below is particularly a camera module for an in-vehicle camera, which is fixedly installed on the exterior surface of a vehicle, with wiring leading into the vehicle and connected to a display or other device.

[0023] As shown in FIG. 1, the camera module 300 of this embodiment is configured by accommodating various optical elements in a housing formed by joining a plurality of housing parts. Specifically, camera module 300 includes, as optical elements, a lens group L in which a plurality of lenses are arranged along the optical axes of the lenses, a cylindrical lens barrel 22 that houses and holds this lens group L, and an image sensor 304 that converts light focused through lens group L into an electrical signal. The housing is made up of a first housing 23 in the shape of a rectangular tube that forms an accommodation space inside to accommodate lens barrel 22 that houses and holds lens group L, a second housing 24 in the shape of a rectangular tube and approximately a thin dish that forms a recess 24g that houses a board 309 on which image sensor 304 is mounted so that image sensor 304 faces lens group L, and that determines the position of image sensor 304 in the optical axis direction, and a third housing 25 in the shape of a rectangular tube that surrounds image sensor module 310 including board 309 from the outside, and an extension 310A extending from image sensor module 310 protrudes outward from third housing 25. The imaging module 310 is formed by combining, for example, the upper substrate 309 on which the imaging element 304 is mounted and a lower substrate on which a circuit for performing image processing is mounted.

[0024] The image-side (lower side in FIG. 1 ) ends of the lens barrel 22 and the first housing 23 are supported by the second housing 24. The length of the second housing 24 in the optical axis direction is shorter than that of the first housing 23. The optical axis is indicated by O, and the direction perpendicular to this optical axis O is the radial direction.

[0025] The first housing 23 is disposed radially outward of the lens barrel 22, and the second housing 24 is disposed closer to the image (lower in FIG. 1 ) than the first housing 23. The lens barrel 22, first housing 23, second housing 24, and third housing 25 are disposed coaxially. A rectangular plate-shaped inner flange portion 24a is formed at the upper end of the second housing 24, and a convex portion 24b that protrudes toward the object side (upper in FIG. 1 ) is formed in the radial center of this inner flange portion 24a, and a through-hole 24c is formed in the radial center of this convex portion 24b.

[0026] A step 24d is formed on the upper surface of the inner flange 24a, and the lower end of the first housing 23 is fitted into this step 24d, thereby positioning the first housing 23 relative to the second housing 24 in the radial direction and the optical axis direction.

[0027] Furthermore, the lens unit 20 including the lens group L and the lens barrel 22 includes a plurality of (e.g., six) lenses 31, 32, 33, 34, 35, and 36 arranged in order from the object side. The lens 31 is a first lens 31 located closest to the object side, and this first lens 31 is held by a lens holding portion 50 (described later) in the first housing 23. The five lenses 32, 33, 34, 35, and 36 arranged closer to the image side than the first lens 31 are provided inside the lens barrel 22.

[0028] Furthermore, a cylindrical protrusion 27 that protrudes toward the image side (downward in FIG. 1) is formed at the lower end of the lens barrel 22, and this protrusion 27 is inserted into and fits into a through-hole 24c provided in the second housing 24. As a result, the lens barrel 22 and the second housing 24 are arranged coaxially and coincident with the optical axis O.

[0029] Furthermore, the first lens 31 located closest to the object is a glass lens, and the lenses 32 to 36 are resin lenses, but this is not limiting (for example, the lens 31 may be a resin lens). Furthermore, the surfaces of the lenses 31 to 36 may be provided with an anti-reflection film, a hydrophilic film, a water-repellent film, or the like, as needed.

[0030] The multiple lenses 31 to 36 fixed to and supported by the lens barrel 22 are arranged with their optical axes aligned, and the lenses 31 to 36 are arranged along a single optical axis O to form a group of lenses L used for imaging.

[0031] In this embodiment, the first housing 23 is disposed radially outward from the lens barrel 22. The first housing 23 is formed from a metal such as SUS and includes a rectangular cylindrical housing main body 23a, a top plate 23b that is short in the radial direction and formed integrally with the housing main body 23a at the upper end of the housing main body 23a, and a locking portion 23c that is formed integrally with the top plate 23b at the inner peripheral edge of the top plate 23b. The thickness of the top plate 23b (thickness in the optical axis direction) is thinner than the thickness of the housing main body 23a (thickness in the radial direction).

[0032] The locking portion 23c includes a generally cylindrical protrusion 23d formed to protrude from the inner peripheral edge of the top plate portion 23b toward the object side (upper side in FIG. 1 ) and a pressing portion 23e bent radially inward from the upper end of the protrusion 23d. An inclined surface 23f inclined with respect to the optical axis O is formed along the circumferential direction on the inner surface of the pressing portion 23e. The inclined surface 23f presses the surface edge of the first lens 31, thereby fixing the first lens 31. In other words, when the lens group L is assembled and housed in the first housing 23 and the lens barrel 22, the inclined surface 23f of the pressing portion 23e presses the first lens 31, which is located closest to the object side of the lens group L, and fixes it to the object-side end of the first housing 23 in the optical axis direction.

[0033] Furthermore, an inner flange portion 26 having an opening with a diameter smaller than that of the sixth lens 36 is provided at the image side end (the lower end in FIG. 1) of the lens barrel 22. The plurality of lenses 31 to 36 that make up the lens group L inside the first housing 23 and the lens barrel 22 are held and fixed in the optical axis direction by this inner flange portion 26 and the inclined surface 23f of the pressing portion 23e. Furthermore, a filter 99 such as an infrared cut filter is provided on the lower surface of the inner flange portion 26.

[0034] In this embodiment, a ring-shaped lens holder 50 is provided to hold the first lens 31. The lens holder 50 is manufactured by turning a metal such as stainless steel into a thin ring shape. The lens holder 50 has an inner peripheral surface 50a that is cylindrical and a toric surface 50b that is perpendicular to the inner peripheral surface 50a. The inner peripheral surface 50a and the toric surface 50b are formed to have an L-shaped cross section. The inner peripheral surface 50a is arranged coaxially with the optical axis O, and the toric surface 50b is arranged perpendicular to the optical axis O. The lens holder 50 also has an inner peripheral surface 50c that is perpendicular to the toric surface 50b and coaxial with the optical axis O. The inner peripheral surface 50c is arranged closer to the image side (lower in FIG. 1 ) than the inner peripheral surface 50a and has a smaller inner diameter than the inner peripheral surface 50a.

[0035] The inner diameter of the inner peripheral surface 50c of the ring-shaped lens holder 50 is larger than the outer diameter of the lens barrel 22, so that the upper end of the lens barrel 22 is located inside the inner peripheral surface 50c of the lens holder 50. The lens holder 50 is also joined to the first housing 23. That is, the outer peripheral surface 50d of the lens holder 50 abuts the inner peripheral surface of the protrusion 23d of the first housing 23 with almost no gap, so that the lens holder 50 fits into the locking portion 23c of the first housing 23. In this way, the lens holder 50 is joined to the first housing 23, which has the locking portion 23c. When the lens holder 50 is joined to the first housing 23, the axis of the lens holder 50 coincides with the optical axis O, and the lens holder 50 is positioned in the optical axis direction.

[0036] The lens holder 50 also holds the first lens 31. That is, the inner peripheral surface 50a of the lens holder 50 abuts tightly against the outer peripheral surface of the first lens 31, thereby positioning the first lens 31 in the radial direction and disposing it coaxially with the optical axis O. The annular surface 50b of the lens holder 50 abuts tightly against the flat bottom surface 31a of the first lens 31 facing the image side, thereby positioning the first lens 31 in the optical axis direction.

[0037] Furthermore, lenses 32 to 36, which are arranged closer to the image than the first lens 31, are held by the lens barrel 22 so that their optical axes are aligned, and the lens barrel 22 is arranged coaxially with the second housing 24 and aligned with the optical axis O, so that the first lens 31 and lenses 32 to 36, which are arranged closer to the image than the first lens 31, are arranged coaxially or with an eccentricity of less than a predetermined amount.

[0038] In this embodiment, a vibration mechanism 60 is provided to vibrate the first lens 31. The vibration mechanism 60 includes a vibrator 61 that generates ultrasonic vibrations and a vibrating body 62 that transmits the ultrasonic vibrations of the vibrator 61 to the first lens 31. The vibration mechanism 60 is housed within the first housing 23, positioned radially inward from the first housing 23 and radially outward from the lens barrel 22. The vibrator 61 is formed in the shape of an annular plate and is provided inside the housing body 23a of the first housing 23. The vibrator 61 is formed, for example, of a piezoelectric element. The vibration mechanism 60 having the vibrator 61 is separated from the second housing 24 by a predetermined gap s to avoid resonance (resonance and the associated noise) due to vibration.

[0039] The vibrating body 62 includes a donut-shaped disk-shaped mounting portion 62a, and a main body portion 62b that extends from the mounting portion 62a toward the object side (upward in FIG. 1), has an outer diameter and an inner diameter that continuously change in the axial direction (optical axis direction), has a generally cylindrical shape with bulges and constrictions, and has an S-shaped cross section. The vibrator 61 is fixed to the underside of the mounting portion 62a, and the upper end side of the main body portion 62b is integrally formed with the lens holder 50 described above.

[0040] In such vibration mechanism 60, vibrator 61 ultrasonically vibrates at a predetermined frequency, causing vibration body 62 to ultrasonically vibrate. When vibration body 62 vibrates, first lens 31 ultrasonically vibrates at the same frequency via lens holder 50 because vibration body 62 is integrated with lens holder 50, thereby removing foreign matter such as water droplets, muddy water, ice, snow, and frost from lens surface 31b of first lens 31.

[0041] The lens holder 50 is fitted into the top plate 23b (locking portion 23c) of the first housing 23, but the thickness of the top plate 23b is thinner than the thickness of the housing main body 23a, and the top plate 23b functions as a damper, so that vibrations of the lens holder 50 are less likely to be transmitted to the housing main body 23a. This makes it less likely that vibrations will be transmitted to the second housing 24 fitted into the housing main body 23a, and as a result, vibrations are less likely to be transmitted to the lens barrel 22 fitted into the second housing 24, and therefore to the lenses 32 to 36, thereby preventing a deterioration in optical performance caused by displacement of the lenses 32 to 36 due to vibrations.

[0042] In this embodiment, the lens unit 20 is made up of the first housing 23, the first lens 31 held in the first housing 23, the lens barrel 22, the lenses 32 to 36 held in the lens barrel 22, the lens holder 50, the vibration mechanism 60, etc. The camera module 300 of this embodiment is made up of the lens unit 20, the second housing 24 fitted into the first housing 23 of the lens unit 20, and the third housing 25 fitted into the second housing 24 and containing the imaging module.

[0043] The second housing 24 and the third housing 25 house therein an imaging module 310 including a board 309 on which an imaging element 304 (image sensor) is mounted. Specifically, the imaging module 310 occupies most of the interior space of the second and third housings 24, 25, and is disposed in the center of the interior of the third housing 25 with the board 309 on which the imaging element 304 (image sensor) is mounted being received and positioned in the recess 24g of the second housing 24.

[0044] The image sensor 304 serving as a package sensor is disposed inside the second housing 24 facing the filter 99, and is disposed in a position where it receives an image of an object formed by the lens unit 20. The image sensor 304 includes a CCD, a CMOS, or the like, and converts light that is collected through the lens unit 20 and reaches the image sensor 304 into an electrical signal. The converted electrical signal is then converted into analog data or digital data, which are components of the image data captured by the camera.

[0045] The third housing 25 also includes a drive circuit board 305 therein. The drive circuit board 305 is a board having a drive circuit that applies a voltage of a predetermined frequency to the piezoelectric element 61 of the vibration mechanism 60 to drive it. The drive circuit board 305 and the vibrator (piezoelectric element) 61 are connected by wiring 306 formed of an FPC or the like and passed through wiring holes 24f formed in the inner flange portion 24a of the second housing 24.

[0046] As described above, with the substrate 309 on which the image sensor 304 is mounted received in the recess 24g, the second housing 24 has a seal member 70 interposed between it and the third housing 25 (at the joint between the second housing 24 and the third housing 25) to keep the internal spaces of the housings 24, 25 communicating with each other airtight, and is fastened to the first housing 23 by a screw 80, as clearly shown in Figures 2 and 3. In this case, the inside of the first housing 23 is densely packed with components including the lens unit 20 and the vibration mechanism 60, as described above, and assembly is also performed in order from the first housing 23 side to the second housing 24 and the third housing 25 side, so the screw 80 is screwed into the threaded portion 79 of the first housing 23 from the second housing 24 side, and the head 80a of the screw 80 is positioned on the second housing 24 side.

[0047] Furthermore, the seal member 70 forms a rectangular annular body that is disposed and fitted around the entire inner outer peripheral edge of the second housing 24, and is fixed to the second housing 24 by the screws 80 at a position where the imaging module 310 and the screws 80 do not interfere with each other. To achieve this, in the present embodiment, the seal member 70 is formed with a plurality of screw engagement portions 90 with which the screws 80 are engaged so as to enable the seal member 70 to be fixed by the screws 80 and to fasten the first and second housings 23, 24 together. In particular, in the present embodiment, the screw engagement portions 90 are formed at the four corners (four vertices of the square) of the rectangular seal member 70 that fits into the rectangular (quadratic) second housing 24.

[0048] The screw engaging portion 90 has an insertion hole 76 for inserting the shank 80b of the screw 80 that passes through the through-hole 89 of the second housing 24 and screws into the threaded portion 79 of the first housing 23, and a washer acting portion (portion that acts as a washer) 77 that is interposed between the head 80a of the screw 80 and the second housing 23 to seat the head 80a of the screw 80. The screw engaging portion 90 also has a peripheral side wall 72 that surrounds the head 80a of the screw 80 all around, thereby forming a recess 73 for embedding the head 80a of the screw 80 inside the seal member 70.

[0049] In this way, in this embodiment, the screw 80, which is screwed into the first housing 23 from the second housing 24 side to fasten the first housing 23 and the second housing 24, itself fixes the sealing member 70 to the second housing 24 at a position that does not interfere with the imaging module 310. Therefore, even in a situation where the installation space for the second housing 24 is limited due to the miniaturization of cameras, the fastening of the housings 23 and 24 to each other by the screw 80 can be ensured without the airtightness inside the housings 24 and 25 provided by the sealing member 70 being compromised by the screw 80.

[0050] FIG. 4 schematically illustrates a vehicle 240 as a moving object equipped with an in-vehicle system (imaging system) including an imaging device 250 including the camera module 300 of FIG. 1 . As illustrated, the imaging device 250 can be mounted on the vehicle 240, and FIG. 4 illustrates an example of the mounting position of the imaging device 250 on the vehicle 240. The imaging device 250 mounted on the vehicle 240 can also be called an in-vehicle camera and can be installed in various locations on the vehicle 240. For example, the first imaging device 250a may be disposed on or near the front bumper as a camera that monitors the front of the vehicle 240 while the vehicle 240 is traveling. The second imaging device 250b that monitors the front of the vehicle 240 may be disposed near an inner rearview mirror inside the vehicle 240. The third imaging device 250c may be disposed on the dashboard, in the instrument panel, or the like as a camera that monitors the driver's driving status. The fourth image capturing device 250d may be installed at the rear of the vehicle 240 to monitor the rear of the vehicle 240. The image capturing devices 250a and 250b may be called front cameras. The third image capturing device 250c may be called an in-camera. The fourth image capturing device 250d may be called a rear camera. The image capturing device 250 is not limited to these, and may include image capturing devices installed at various positions, such as a left side camera that captures the left rear side and a right side camera that captures the right rear side.

[0051] An image signal of an image captured by the imaging device 250 may be output to an information processing device (controller) 242 and / or a display device (output device) 243 in the vehicle 240. The information processing device 242 and the display device 243, together with the imaging device 250, constitute an in-vehicle system. The information processing device 242 in the vehicle 240 includes a device that processes the image signal (captured image) acquired by the imaging device 250 and recognizes the image (recognizing objects in the captured image) to assist the driver in driving. The information processing device 242 is configured to output recognition information of objects in the captured image to the display device 243, and examples of such devices include, but are not limited to, a navigation system, a collision damage mitigation braking system, a vehicle-to-vehicle distance control device, and a lane departure warning system. The display device 243 displays the image processed and output by the information processing device 242, but can also receive an image signal directly from the imaging device 250. The display device 243 may be, but is not limited to, a liquid crystal display (LCD), an organic electroluminescence (EL) display, or an inorganic EL display. The display device 243 can display to the driver (can output information to the occupants) an image signal output from an imaging device 250 that captures an image from a position that is difficult for the driver to see, such as a rear camera.

[0052] Fig. 5 shows the configuration of an imaging device that constitutes the in-vehicle system of Fig. 4. As shown in the figure, an imaging device 250 according to one embodiment includes a control unit 252, a storage unit 254, and the camera module 300 of Fig. 1 described above.

[0053] The control unit 252 controls the camera module 300 and processes the electrical signal output from the image sensor 304 of the camera module 300. The control unit 252 may be configured as, for example, a processor. The control unit 252 may also include one or more processors. The processor may include a general-purpose processor that loads a specific program to execute a specific function, and a dedicated processor specialized for a specific process. The dedicated processor may include an application-specific integrated circuit (IC). An application-specific IC is also called an application-specific integrated circuit (ASIC). The processor may include a programmable logic device. A programmable logic device is also called a programmable logic device (PLD). A PLD may include a field-programmable gate array (FPGA). The control unit 252 may be either a system-on-a-chip (SoC) or a system-in-a-package (SiP) in which one or more processors work together. In addition, the control unit 252 may have the same functions as the information processing device 242 described above, and may, for example, process the captured image output from the image sensor 304 and recognize objects in the captured image.

[0054] The storage unit 254 stores various information or parameters related to the operation of the imaging device 250. The storage unit 254 may be configured with, for example, a semiconductor memory or the like. The storage unit 254 may function as a work memory for the control unit 252. The storage unit 254 may store captured images. The storage unit 254 may store various parameters and the like that are used by the control unit 252 to perform detection processing based on the captured images. The storage unit 254 may be included in the control unit 252.

[0055] As described above, the camera module 300 captures an image of a subject formed through the lens unit 20 with the image sensor 304 and outputs the captured image. The image captured by the camera module 300 is also referred to as a captured image.

[0056] The imaging element 304 may be configured, for example, as a complementary metal oxide semiconductor (CMOS) image sensor or a charge coupled device (CCD). The imaging element 304 has an imaging surface on which a plurality of pixels are arranged. Each pixel outputs a signal specified by a current or voltage according to the amount of incident light. The signal output by each pixel is also referred to as imaging data.

[0057] The imaging data may be read by the camera module 300 for all pixels and captured by the control unit 252 as a captured image. A captured image read by all pixels is also referred to as a maximum captured image. The imaging data may be read by the camera module 300 for some pixels and captured as a captured image. In other words, the imaging data may be read from pixels in a predetermined capture range. The imaging data read from pixels in the predetermined capture range may be captured as a captured image. The predetermined capture range may be set by the control unit 252. The camera module 300 may acquire the predetermined capture range from the control unit 252. The imaging element 304 may capture an image of a predetermined capture range from the subject image formed via the lens unit 20.

[0058] The present invention is not limited to the above-described embodiments and can be modified in various ways without departing from the spirit of the invention. For example, the shapes of the lens, housing, lens barrel, etc. are not limited to those of the above-described embodiments. Furthermore, some or all of the above-described embodiments may be combined, or part of the configuration of one of the above-described embodiments may be omitted, without departing from the spirit of the invention.

[0059] 20 Lens unit 22 Lens barrel 23 First housing 24 Second housing 25 Third housing 31 First lens 60 Vibration mechanism 70 Sealing member 72 Peripheral side wall 73 Recess 76 Insertion hole 77 Washer action portion 80 Screw 80a Head 80b Shank 90 Screw engagement portion 300 Camera module 304 Image pickup element 310 Image pickup module L Lens group

Claims

1. A camera module comprising a lens group in which multiple lenses are arranged along the optical axes of the lenses, a lens barrel that houses and holds this lens group, and an image sensor that converts light focused through the lens group into an electrical signal, comprising: a cylindrical first housing that forms an internal storage space to receive the lens barrel that houses and holds the lens group; a second housing that is coupled to the image side of the first housing and forms a recess that receives a board on which the image sensor is mounted so that the image sensor faces the lens group; a cylindrical third housing that is coupled to the image side of the second housing and surrounds the image sensor module including the board from the outside; screws that are screwed into the first housing from the second housing side to fasten the first housing and the second housing together; and a seal member that is interposed between the second housing and the third housing, wherein the seal member is arranged around the entire circumference so as to follow the inner outer periphery of the second housing, and is fixed to the second housing by the screws in a position where the image sensor and the screws do not interfere with each other.

2. The camera module described in claim 1, characterized in that the sealing member forms a plurality of screw engagement portions into which the screws engage so as to enable the sealing member to be fixed by the screws and the first and second housings to be fastened together.

3. The camera module described in claim 2, characterized in that the screw engagement portion has an insertion hole for inserting the shank of the screw that penetrates the second housing and screws into the first housing, and a washer operating portion that is interposed between the head of the screw and the second housing.

4. The camera module according to claim 3, wherein said screw engagement portion forms a peripheral side wall that surrounds the entire periphery of the head of said screw.

5. The camera module according to claim 4, wherein the screw engagement portion forms a recess for embedding the head of the screw inside the sealing member.

6. The camera module according to claim 1, further comprising a vibration mechanism in the first housing, the vibration mechanism having a vibrating body for vibrating the first lens of the lens group that is positioned closest to the object.

7. An in-vehicle system to be mounted on a vehicle, comprising: a camera module according to any one of claims 1 to 6; and a control unit that processes an image output from the imaging element of the camera module and recognizes an object in the image.

8. A mobile body equipped with the in-vehicle system according to claim 7 and an output device that outputs information to an occupant, wherein the control unit is configured to output the recognition information of the object to the output device.

Images